Discipline: Biological Sciences
Subcategory: Cancer Research
Tamirat Ali - University of Minnesota
Co-Author(s): Janielle Maynard, Johns Hopkins Medicine, Baltimore, MD; Karen Sfanos, Johns Hopkins Medicine , Baltimore, MD
Prostate Cancer (PCa) is the third leading cause of cancer deaths in American men. Interestingly, African American (AA) men are more likely to be diagnosed with advanced PCa and are 2-3 times more likely to die from the disease than Caucasian American (CA) men. There is a recent hypothesis that correlates chronic inflammation and prostate carcinogenesis. In favor of this hypothesis, there is often a high amount of inflammation observed in prostate cancer specimens, and evidence suggests that intraprostatic inflammation may be associated with prostate cancer development and/or progression. Increased inflammatory related genes have been reported in AA compared to CA men with PCa. Looking closer, inflammation results in cell injury which may cause ATP release from cells into the extracellular milieu. Recently, extracellular ATP has been implicated in the promotion of inflammation, cell proliferation, migration and invasion via activation of P2 purinergic receptors: ligand-gated ion-channel P2X receptors and G protein-coupled P2Y receptors. P2 purinergic receptors are membrane-bound and are found in both excitable and non-excitable cells throughout the body. Studies have shown the involvement of P2 purinergic receptors in multiple types of cancer. Particularly in prostate cancer, P2X7 and P2Y2 activation has been reported to increase the invasiveness of prostate cancer cells. Among the P2X family of P2 purinergic receptors, P2X4 is highly expressed in prostatic carcinoma, suggesting a possible role in prostate cancer pathogenesis. The exact mechanism as to how P2X4 receptors contribute to the development and progression of prostate cancer is yet to be resolved. In this study, we hypothesized that extracellular nucleotide activation of P2X4 purinergic receptors promotes prostate cancer cell migration and invasion. To examine this, CA derived PC3 and CWR22Rv1 and AA derived E006AA PCa cell lines were evaluated for effects of extracellular nucleotide treatment on cell migration and invasion. Transwell matrigel invasion and migration assays were used to evaluate prostate cancer cell migration and invasion in response to nucleotide treatment. Fluorescence microscopy was used to visualize migrated and invaded cells and ImageJ software used to count these cells. Results showed significantly increased cell migration and invasion upon nucleotide treatment (24-72h) in all 3 cell lines. 48h treatment most strongly induced migration and invasion (up to 9.6- fold, p=2.1E-6). Particularly in PC3 cells, CTP (P2X4 agonist) more strongly induced cell invasion (4.1- fold, p=4.02E08) than ATP (universal P2 receptor agonist) (2.7- fold, p=1.4E-05). In conclusion, nucleotide treatment alone is sufficient to induce cell migration and invasion in prostate cancer cells, and this implies that P2X4 receptors likely facilitate prostate cancer cell migration and invasion.
Not SubmittedFunder Acknowledgement(s): U.S. Department of Health and Human Services Health Careers Opportunity Program Grant Number D18HP29037
Faculty Advisor: Karen Sfanos, ksandel1@jhmi.edu
Role: Transwell matrigel invasion assay ; Transwell matrigel migration assay ; Fluorescence microscopy; Used ImageJ software to count migrated and invaded cells ; Analyzed count using excel